diff options
Diffstat (limited to '')
| -rw-r--r-- | net/ipv6/udp.c | 1839 |
1 files changed, 1839 insertions, 0 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c new file mode 100644 index 000000000..c2c02dea6 --- /dev/null +++ b/net/ipv6/udp.c @@ -0,0 +1,1839 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * UDP over IPv6 + * Linux INET6 implementation + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * + * Based on linux/ipv4/udp.c + * + * Fixes: + * Hideaki YOSHIFUJI : sin6_scope_id support + * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which + * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind + * a single port at the same time. + * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data + * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file. + */ + +#include <linux/bpf-cgroup.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/in6.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/ipv6.h> +#include <linux/icmpv6.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/indirect_call_wrapper.h> + +#include <net/addrconf.h> +#include <net/ndisc.h> +#include <net/protocol.h> +#include <net/transp_v6.h> +#include <net/ip6_route.h> +#include <net/raw.h> +#include <net/seg6.h> +#include <net/tcp_states.h> +#include <net/ip6_checksum.h> +#include <net/ip6_tunnel.h> +#include <net/xfrm.h> +#include <net/inet_hashtables.h> +#include <net/inet6_hashtables.h> +#include <net/busy_poll.h> +#include <net/sock_reuseport.h> + +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <trace/events/skb.h> +#include "udp_impl.h" + +static void udpv6_destruct_sock(struct sock *sk) +{ + udp_destruct_common(sk); + inet6_sock_destruct(sk); +} + +int udpv6_init_sock(struct sock *sk) +{ + skb_queue_head_init(&udp_sk(sk)->reader_queue); + sk->sk_destruct = udpv6_destruct_sock; + set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags); + return 0; +} + +static u32 udp6_ehashfn(const struct net *net, + const struct in6_addr *laddr, + const u16 lport, + const struct in6_addr *faddr, + const __be16 fport) +{ + static u32 udp6_ehash_secret __read_mostly; + static u32 udp_ipv6_hash_secret __read_mostly; + + u32 lhash, fhash; + + net_get_random_once(&udp6_ehash_secret, + sizeof(udp6_ehash_secret)); + net_get_random_once(&udp_ipv6_hash_secret, + sizeof(udp_ipv6_hash_secret)); + + lhash = (__force u32)laddr->s6_addr32[3]; + fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); + + return __inet6_ehashfn(lhash, lport, fhash, fport, + udp6_ehash_secret + net_hash_mix(net)); +} + +int udp_v6_get_port(struct sock *sk, unsigned short snum) +{ + unsigned int hash2_nulladdr = + ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum); + unsigned int hash2_partial = + ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0); + + /* precompute partial secondary hash */ + udp_sk(sk)->udp_portaddr_hash = hash2_partial; + return udp_lib_get_port(sk, snum, hash2_nulladdr); +} + +void udp_v6_rehash(struct sock *sk) +{ + u16 new_hash = ipv6_portaddr_hash(sock_net(sk), + &sk->sk_v6_rcv_saddr, + inet_sk(sk)->inet_num); + + udp_lib_rehash(sk, new_hash); +} + +static int compute_score(struct sock *sk, struct net *net, + const struct in6_addr *saddr, __be16 sport, + const struct in6_addr *daddr, unsigned short hnum, + int dif, int sdif) +{ + int bound_dev_if, score; + struct inet_sock *inet; + bool dev_match; + + if (!net_eq(sock_net(sk), net) || + udp_sk(sk)->udp_port_hash != hnum || + sk->sk_family != PF_INET6) + return -1; + + if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) + return -1; + + score = 0; + inet = inet_sk(sk); + + if (inet->inet_dport) { + if (inet->inet_dport != sport) + return -1; + score++; + } + + if (!ipv6_addr_any(&sk->sk_v6_daddr)) { + if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) + return -1; + score++; + } + + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + dev_match = udp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif); + if (!dev_match) + return -1; + if (bound_dev_if) + score++; + + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) + score++; + + return score; +} + +static struct sock *lookup_reuseport(struct net *net, struct sock *sk, + struct sk_buff *skb, + const struct in6_addr *saddr, + __be16 sport, + const struct in6_addr *daddr, + unsigned int hnum) +{ + struct sock *reuse_sk = NULL; + u32 hash; + + if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { + hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); + reuse_sk = reuseport_select_sock(sk, hash, skb, + sizeof(struct udphdr)); + } + return reuse_sk; +} + +/* called with rcu_read_lock() */ +static struct sock *udp6_lib_lookup2(struct net *net, + const struct in6_addr *saddr, __be16 sport, + const struct in6_addr *daddr, unsigned int hnum, + int dif, int sdif, struct udp_hslot *hslot2, + struct sk_buff *skb) +{ + struct sock *sk, *result; + int score, badness; + + result = NULL; + badness = -1; + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + score = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); + if (score > badness) { + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + + /* Fall back to scoring if group has connections */ + if (!reuseport_has_conns(sk)) + return result; + + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); + } + } + return result; +} + +static inline struct sock *udp6_lookup_run_bpf(struct net *net, + struct udp_table *udptable, + struct sk_buff *skb, + const struct in6_addr *saddr, + __be16 sport, + const struct in6_addr *daddr, + u16 hnum, const int dif) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (udptable != &udp_table) + return NULL; /* only UDP is supported */ + + no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP, saddr, sport, + daddr, hnum, dif, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + +/* rcu_read_lock() must be held */ +struct sock *__udp6_lib_lookup(struct net *net, + const struct in6_addr *saddr, __be16 sport, + const struct in6_addr *daddr, __be16 dport, + int dif, int sdif, struct udp_table *udptable, + struct sk_buff *skb) +{ + unsigned short hnum = ntohs(dport); + unsigned int hash2, slot2; + struct udp_hslot *hslot2; + struct sock *result, *sk; + + hash2 = ipv6_portaddr_hash(net, daddr, hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + /* Lookup connected or non-wildcard sockets */ + result = udp6_lib_lookup2(net, saddr, sport, + daddr, hnum, dif, sdif, + hslot2, skb); + if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) + goto done; + + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + sk = udp6_lookup_run_bpf(net, udptable, skb, + saddr, sport, daddr, hnum, dif); + if (sk) { + result = sk; + goto done; + } + } + + /* Got non-wildcard socket or error on first lookup */ + if (result) + goto done; + + /* Lookup wildcard sockets */ + hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + result = udp6_lib_lookup2(net, saddr, sport, + &in6addr_any, hnum, dif, sdif, + hslot2, skb); +done: + if (IS_ERR(result)) + return NULL; + return result; +} +EXPORT_SYMBOL_GPL(__udp6_lib_lookup); + +static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, + __be16 sport, __be16 dport, + struct udp_table *udptable) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + + return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, + &iph->daddr, dport, inet6_iif(skb), + inet6_sdif(skb), udptable, skb); +} + +struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb, + __be16 sport, __be16 dport) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + + return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, + &iph->daddr, dport, inet6_iif(skb), + inet6_sdif(skb), &udp_table, NULL); +} + +/* Must be called under rcu_read_lock(). + * Does increment socket refcount. + */ +#if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6) +struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, + const struct in6_addr *daddr, __be16 dport, int dif) +{ + struct sock *sk; + + sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, + dif, 0, &udp_table, NULL); + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) + sk = NULL; + return sk; +} +EXPORT_SYMBOL_GPL(udp6_lib_lookup); +#endif + +/* do not use the scratch area len for jumbogram: their length execeeds the + * scratch area space; note that the IP6CB flags is still in the first + * cacheline, so checking for jumbograms is cheap + */ +static int udp6_skb_len(struct sk_buff *skb) +{ + return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); +} + +/* + * This should be easy, if there is something there we + * return it, otherwise we block. + */ + +int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int flags, int *addr_len) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct inet_sock *inet = inet_sk(sk); + struct sk_buff *skb; + unsigned int ulen, copied; + int off, err, peeking = flags & MSG_PEEK; + int is_udplite = IS_UDPLITE(sk); + struct udp_mib __percpu *mib; + bool checksum_valid = false; + int is_udp4; + + if (flags & MSG_ERRQUEUE) + return ipv6_recv_error(sk, msg, len, addr_len); + + if (np->rxpmtu && np->rxopt.bits.rxpmtu) + return ipv6_recv_rxpmtu(sk, msg, len, addr_len); + +try_again: + off = sk_peek_offset(sk, flags); + skb = __skb_recv_udp(sk, flags, &off, &err); + if (!skb) + return err; + + ulen = udp6_skb_len(skb); + copied = len; + if (copied > ulen - off) + copied = ulen - off; + else if (copied < ulen) + msg->msg_flags |= MSG_TRUNC; + + is_udp4 = (skb->protocol == htons(ETH_P_IP)); + mib = __UDPX_MIB(sk, is_udp4); + + /* + * If checksum is needed at all, try to do it while copying the + * data. If the data is truncated, or if we only want a partial + * coverage checksum (UDP-Lite), do it before the copy. + */ + + if (copied < ulen || peeking || + (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { + checksum_valid = udp_skb_csum_unnecessary(skb) || + !__udp_lib_checksum_complete(skb); + if (!checksum_valid) + goto csum_copy_err; + } + + if (checksum_valid || udp_skb_csum_unnecessary(skb)) { + if (udp_skb_is_linear(skb)) + err = copy_linear_skb(skb, copied, off, &msg->msg_iter); + else + err = skb_copy_datagram_msg(skb, off, msg, copied); + } else { + err = skb_copy_and_csum_datagram_msg(skb, off, msg); + if (err == -EINVAL) + goto csum_copy_err; + } + if (unlikely(err)) { + if (!peeking) { + atomic_inc(&sk->sk_drops); + SNMP_INC_STATS(mib, UDP_MIB_INERRORS); + } + kfree_skb(skb); + return err; + } + if (!peeking) + SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS); + + sock_recv_cmsgs(msg, sk, skb); + + /* Copy the address. */ + if (msg->msg_name) { + DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); + sin6->sin6_family = AF_INET6; + sin6->sin6_port = udp_hdr(skb)->source; + sin6->sin6_flowinfo = 0; + + if (is_udp4) { + ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, + &sin6->sin6_addr); + sin6->sin6_scope_id = 0; + } else { + sin6->sin6_addr = ipv6_hdr(skb)->saddr; + sin6->sin6_scope_id = + ipv6_iface_scope_id(&sin6->sin6_addr, + inet6_iif(skb)); + } + *addr_len = sizeof(*sin6); + + BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, + (struct sockaddr *)sin6); + } + + if (udp_test_bit(GRO_ENABLED, sk)) + udp_cmsg_recv(msg, sk, skb); + + if (np->rxopt.all) + ip6_datagram_recv_common_ctl(sk, msg, skb); + + if (is_udp4) { + if (inet->cmsg_flags) + ip_cmsg_recv_offset(msg, sk, skb, + sizeof(struct udphdr), off); + } else { + if (np->rxopt.all) + ip6_datagram_recv_specific_ctl(sk, msg, skb); + } + + err = copied; + if (flags & MSG_TRUNC) + err = ulen; + + skb_consume_udp(sk, skb, peeking ? -err : err); + return err; + +csum_copy_err: + if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, + udp_skb_destructor)) { + SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS); + SNMP_INC_STATS(mib, UDP_MIB_INERRORS); + } + kfree_skb(skb); + + /* starting over for a new packet, but check if we need to yield */ + cond_resched(); + msg->msg_flags &= ~MSG_TRUNC; + goto try_again; +} + +DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); +void udpv6_encap_enable(void) +{ + static_branch_inc(&udpv6_encap_needed_key); +} +EXPORT_SYMBOL(udpv6_encap_enable); + +/* Handler for tunnels with arbitrary destination ports: no socket lookup, go + * through error handlers in encapsulations looking for a match. + */ +static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb, + struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + int i; + + for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { + int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info); + const struct ip6_tnl_encap_ops *encap; + + encap = rcu_dereference(ip6tun_encaps[i]); + if (!encap) + continue; + handler = encap->err_handler; + if (handler && !handler(skb, opt, type, code, offset, info)) + return 0; + } + + return -ENOENT; +} + +/* Try to match ICMP errors to UDP tunnels by looking up a socket without + * reversing source and destination port: this will match tunnels that force the + * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that + * lwtunnels might actually break this assumption by being configured with + * different destination ports on endpoints, in this case we won't be able to + * trace ICMP messages back to them. + * + * If this doesn't match any socket, probe tunnels with arbitrary destination + * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port + * we've sent packets to won't necessarily match the local destination port. + * + * Then ask the tunnel implementation to match the error against a valid + * association. + * + * Return an error if we can't find a match, the socket if we need further + * processing, zero otherwise. + */ +static struct sock *__udp6_lib_err_encap(struct net *net, + const struct ipv6hdr *hdr, int offset, + struct udphdr *uh, + struct udp_table *udptable, + struct sock *sk, + struct sk_buff *skb, + struct inet6_skb_parm *opt, + u8 type, u8 code, __be32 info) +{ + int (*lookup)(struct sock *sk, struct sk_buff *skb); + int network_offset, transport_offset; + struct udp_sock *up; + + network_offset = skb_network_offset(skb); + transport_offset = skb_transport_offset(skb); + + /* Network header needs to point to the outer IPv6 header inside ICMP */ + skb_reset_network_header(skb); + + /* Transport header needs to point to the UDP header */ + skb_set_transport_header(skb, offset); + + if (sk) { + up = udp_sk(sk); + + lookup = READ_ONCE(up->encap_err_lookup); + if (lookup && lookup(sk, skb)) + sk = NULL; + + goto out; + } + + sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source, + &hdr->saddr, uh->dest, + inet6_iif(skb), 0, udptable, skb); + if (sk) { + up = udp_sk(sk); + + lookup = READ_ONCE(up->encap_err_lookup); + if (!lookup || lookup(sk, skb)) + sk = NULL; + } + +out: + if (!sk) { + sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code, + offset, info)); + } + + skb_set_transport_header(skb, transport_offset); + skb_set_network_header(skb, network_offset); + + return sk; +} + +int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info, + struct udp_table *udptable) +{ + struct ipv6_pinfo *np; + const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; + const struct in6_addr *saddr = &hdr->saddr; + const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr; + struct udphdr *uh = (struct udphdr *)(skb->data+offset); + bool tunnel = false; + struct sock *sk; + int harderr; + int err; + struct net *net = dev_net(skb->dev); + + sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, + inet6_iif(skb), inet6_sdif(skb), udptable, NULL); + + if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) { + /* No socket for error: try tunnels before discarding */ + if (static_branch_unlikely(&udpv6_encap_needed_key)) { + sk = __udp6_lib_err_encap(net, hdr, offset, uh, + udptable, sk, skb, + opt, type, code, info); + if (!sk) + return 0; + } else + sk = ERR_PTR(-ENOENT); + + if (IS_ERR(sk)) { + __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), + ICMP6_MIB_INERRORS); + return PTR_ERR(sk); + } + + tunnel = true; + } + + harderr = icmpv6_err_convert(type, code, &err); + np = inet6_sk(sk); + + if (type == ICMPV6_PKT_TOOBIG) { + if (!ip6_sk_accept_pmtu(sk)) + goto out; + ip6_sk_update_pmtu(skb, sk, info); + if (np->pmtudisc != IPV6_PMTUDISC_DONT) + harderr = 1; + } + if (type == NDISC_REDIRECT) { + if (tunnel) { + ip6_redirect(skb, sock_net(sk), inet6_iif(skb), + READ_ONCE(sk->sk_mark), sk->sk_uid); + } else { + ip6_sk_redirect(skb, sk); + } + goto out; + } + + /* Tunnels don't have an application socket: don't pass errors back */ + if (tunnel) { + if (udp_sk(sk)->encap_err_rcv) + udp_sk(sk)->encap_err_rcv(sk, skb, offset); + goto out; + } + + if (!np->recverr) { + if (!harderr || sk->sk_state != TCP_ESTABLISHED) + goto out; + } else { + ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); + } + + sk->sk_err = err; + sk_error_report(sk); +out: + return 0; +} + +static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + if (!ipv6_addr_any(&sk->sk_v6_daddr)) { + sock_rps_save_rxhash(sk, skb); + sk_mark_napi_id(sk, skb); + sk_incoming_cpu_update(sk); + } else { + sk_mark_napi_id_once(sk, skb); + } + + rc = __udp_enqueue_schedule_skb(sk, skb); + if (rc < 0) { + int is_udplite = IS_UDPLITE(sk); + enum skb_drop_reason drop_reason; + + /* Note that an ENOMEM error is charged twice */ + if (rc == -ENOMEM) { + UDP6_INC_STATS(sock_net(sk), + UDP_MIB_RCVBUFERRORS, is_udplite); + drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF; + } else { + UDP6_INC_STATS(sock_net(sk), + UDP_MIB_MEMERRORS, is_udplite); + drop_reason = SKB_DROP_REASON_PROTO_MEM; + } + UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + kfree_skb_reason(skb, drop_reason); + return -1; + } + + return 0; +} + +static __inline__ int udpv6_err(struct sk_buff *skb, + struct inet6_skb_parm *opt, u8 type, + u8 code, int offset, __be32 info) +{ + return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); +} + +static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) +{ + enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; + struct udp_sock *up = udp_sk(sk); + int is_udplite = IS_UDPLITE(sk); + + if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) { + drop_reason = SKB_DROP_REASON_XFRM_POLICY; + goto drop; + } + nf_reset_ct(skb); + + if (static_branch_unlikely(&udpv6_encap_needed_key) && + READ_ONCE(up->encap_type)) { + int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); + + /* + * This is an encapsulation socket so pass the skb to + * the socket's udp_encap_rcv() hook. Otherwise, just + * fall through and pass this up the UDP socket. + * up->encap_rcv() returns the following value: + * =0 if skb was successfully passed to the encap + * handler or was discarded by it. + * >0 if skb should be passed on to UDP. + * <0 if skb should be resubmitted as proto -N + */ + + /* if we're overly short, let UDP handle it */ + encap_rcv = READ_ONCE(up->encap_rcv); + if (encap_rcv) { + int ret; + + /* Verify checksum before giving to encap */ + if (udp_lib_checksum_complete(skb)) + goto csum_error; + + ret = encap_rcv(sk, skb); + if (ret <= 0) { + __UDP6_INC_STATS(sock_net(sk), + UDP_MIB_INDATAGRAMS, + is_udplite); + return -ret; + } + } + + /* FALLTHROUGH -- it's a UDP Packet */ + } + + /* + * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). + */ + if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { + + if (up->pcrlen == 0) { /* full coverage was set */ + net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", + UDP_SKB_CB(skb)->cscov, skb->len); + goto drop; + } + if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { + net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", + UDP_SKB_CB(skb)->cscov, up->pcrlen); + goto drop; + } + } + + prefetch(&sk->sk_rmem_alloc); + if (rcu_access_pointer(sk->sk_filter) && + udp_lib_checksum_complete(skb)) + goto csum_error; + + if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) { + drop_reason = SKB_DROP_REASON_SOCKET_FILTER; + goto drop; + } + + udp_csum_pull_header(skb); + + skb_dst_drop(skb); + + return __udpv6_queue_rcv_skb(sk, skb); + +csum_error: + drop_reason = SKB_DROP_REASON_UDP_CSUM; + __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); +drop: + __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + atomic_inc(&sk->sk_drops); + kfree_skb_reason(skb, drop_reason); + return -1; +} + +static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *next, *segs; + int ret; + + if (likely(!udp_unexpected_gso(sk, skb))) + return udpv6_queue_rcv_one_skb(sk, skb); + + __skb_push(skb, -skb_mac_offset(skb)); + segs = udp_rcv_segment(sk, skb, false); + skb_list_walk_safe(segs, skb, next) { + __skb_pull(skb, skb_transport_offset(skb)); + + udp_post_segment_fix_csum(skb); + ret = udpv6_queue_rcv_one_skb(sk, skb); + if (ret > 0) + ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret, + true); + } + return 0; +} + +static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, + __be16 loc_port, const struct in6_addr *loc_addr, + __be16 rmt_port, const struct in6_addr *rmt_addr, + int dif, int sdif, unsigned short hnum) +{ + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net)) + return false; + + if (udp_sk(sk)->udp_port_hash != hnum || + sk->sk_family != PF_INET6 || + (inet->inet_dport && inet->inet_dport != rmt_port) || + (!ipv6_addr_any(&sk->sk_v6_daddr) && + !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || + !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) || + (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && + !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) + return false; + if (!inet6_mc_check(sk, loc_addr, rmt_addr)) + return false; + return true; +} + +static void udp6_csum_zero_error(struct sk_buff *skb) +{ + /* RFC 2460 section 8.1 says that we SHOULD log + * this error. Well, it is reasonable. + */ + net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", + &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), + &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); +} + +/* + * Note: called only from the BH handler context, + * so we don't need to lock the hashes. + */ +static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, + const struct in6_addr *saddr, const struct in6_addr *daddr, + struct udp_table *udptable, int proto) +{ + struct sock *sk, *first = NULL; + const struct udphdr *uh = udp_hdr(skb); + unsigned short hnum = ntohs(uh->dest); + struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); + unsigned int offset = offsetof(typeof(*sk), sk_node); + unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); + int dif = inet6_iif(skb); + int sdif = inet6_sdif(skb); + struct hlist_node *node; + struct sk_buff *nskb; + + if (use_hash2) { + hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) & + udptable->mask; + hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask; +start_lookup: + hslot = &udptable->hash2[hash2]; + offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); + } + + sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { + if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, + uh->source, saddr, dif, sdif, + hnum)) + continue; + /* If zero checksum and no_check is not on for + * the socket then skip it. + */ + if (!uh->check && !udp_get_no_check6_rx(sk)) + continue; + if (!first) { + first = sk; + continue; + } + nskb = skb_clone(skb, GFP_ATOMIC); + if (unlikely(!nskb)) { + atomic_inc(&sk->sk_drops); + __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, + IS_UDPLITE(sk)); + __UDP6_INC_STATS(net, UDP_MIB_INERRORS, + IS_UDPLITE(sk)); + continue; + } + + if (udpv6_queue_rcv_skb(sk, nskb) > 0) + consume_skb(nskb); + } + + /* Also lookup *:port if we are using hash2 and haven't done so yet. */ + if (use_hash2 && hash2 != hash2_any) { + hash2 = hash2_any; + goto start_lookup; + } + + if (first) { + if (udpv6_queue_rcv_skb(first, skb) > 0) + consume_skb(skb); + } else { + kfree_skb(skb); + __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, + proto == IPPROTO_UDPLITE); + } + return 0; +} + +static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) +{ + if (udp_sk_rx_dst_set(sk, dst)) { + const struct rt6_info *rt = (const struct rt6_info *)dst; + + sk->sk_rx_dst_cookie = rt6_get_cookie(rt); + } +} + +/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and + * return code conversion for ip layer consumption + */ +static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, + struct udphdr *uh) +{ + int ret; + + if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) + skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo); + + ret = udpv6_queue_rcv_skb(sk, skb); + + /* a return value > 0 means to resubmit the input */ + if (ret > 0) + return ret; + return 0; +} + +int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, + int proto) +{ + enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; + const struct in6_addr *saddr, *daddr; + struct net *net = dev_net(skb->dev); + struct udphdr *uh; + struct sock *sk; + bool refcounted; + u32 ulen = 0; + + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto discard; + + saddr = &ipv6_hdr(skb)->saddr; + daddr = &ipv6_hdr(skb)->daddr; + uh = udp_hdr(skb); + + ulen = ntohs(uh->len); + if (ulen > skb->len) + goto short_packet; + + if (proto == IPPROTO_UDP) { + /* UDP validates ulen. */ + + /* Check for jumbo payload */ + if (ulen == 0) + ulen = skb->len; + + if (ulen < sizeof(*uh)) + goto short_packet; + + if (ulen < skb->len) { + if (pskb_trim_rcsum(skb, ulen)) + goto short_packet; + saddr = &ipv6_hdr(skb)->saddr; + daddr = &ipv6_hdr(skb)->daddr; + uh = udp_hdr(skb); + } + } + + if (udp6_csum_init(skb, uh, proto)) + goto csum_error; + + /* Check if the socket is already available, e.g. due to early demux */ + sk = skb_steal_sock(skb, &refcounted); + if (sk) { + struct dst_entry *dst = skb_dst(skb); + int ret; + + if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst)) + udp6_sk_rx_dst_set(sk, dst); + + if (!uh->check && !udp_get_no_check6_rx(sk)) { + if (refcounted) + sock_put(sk); + goto report_csum_error; + } + + ret = udp6_unicast_rcv_skb(sk, skb, uh); + if (refcounted) + sock_put(sk); + return ret; + } + + /* + * Multicast receive code + */ + if (ipv6_addr_is_multicast(daddr)) + return __udp6_lib_mcast_deliver(net, skb, + saddr, daddr, udptable, proto); + + /* Unicast */ + sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); + if (sk) { + if (!uh->check && !udp_get_no_check6_rx(sk)) + goto report_csum_error; + return udp6_unicast_rcv_skb(sk, skb, uh); + } + + reason = SKB_DROP_REASON_NO_SOCKET; + + if (!uh->check) + goto report_csum_error; + + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto discard; + nf_reset_ct(skb); + + if (udp_lib_checksum_complete(skb)) + goto csum_error; + + __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); + icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); + + kfree_skb_reason(skb, reason); + return 0; + +short_packet: + if (reason == SKB_DROP_REASON_NOT_SPECIFIED) + reason = SKB_DROP_REASON_PKT_TOO_SMALL; + net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", + proto == IPPROTO_UDPLITE ? "-Lite" : "", + saddr, ntohs(uh->source), + ulen, skb->len, + daddr, ntohs(uh->dest)); + goto discard; + +report_csum_error: + udp6_csum_zero_error(skb); +csum_error: + if (reason == SKB_DROP_REASON_NOT_SPECIFIED) + reason = SKB_DROP_REASON_UDP_CSUM; + __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); +discard: + __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); + kfree_skb_reason(skb, reason); + return 0; +} + + +static struct sock *__udp6_lib_demux_lookup(struct net *net, + __be16 loc_port, const struct in6_addr *loc_addr, + __be16 rmt_port, const struct in6_addr *rmt_addr, + int dif, int sdif) +{ + unsigned short hnum = ntohs(loc_port); + unsigned int hash2, slot2; + struct udp_hslot *hslot2; + __portpair ports; + struct sock *sk; + + hash2 = ipv6_portaddr_hash(net, loc_addr, hnum); + slot2 = hash2 & udp_table.mask; + hslot2 = &udp_table.hash2[slot2]; + ports = INET_COMBINED_PORTS(rmt_port, hnum); + + udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { + if (sk->sk_state == TCP_ESTABLISHED && + inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif)) + return sk; + /* Only check first socket in chain */ + break; + } + return NULL; +} + +void udp_v6_early_demux(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + const struct udphdr *uh; + struct sock *sk; + struct dst_entry *dst; + int dif = skb->dev->ifindex; + int sdif = inet6_sdif(skb); + + if (!pskb_may_pull(skb, skb_transport_offset(skb) + + sizeof(struct udphdr))) + return; + + uh = udp_hdr(skb); + + if (skb->pkt_type == PACKET_HOST) + sk = __udp6_lib_demux_lookup(net, uh->dest, + &ipv6_hdr(skb)->daddr, + uh->source, &ipv6_hdr(skb)->saddr, + dif, sdif); + else + return; + + if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) + return; + + skb->sk = sk; + skb->destructor = sock_efree; + dst = rcu_dereference(sk->sk_rx_dst); + + if (dst) + dst = dst_check(dst, sk->sk_rx_dst_cookie); + if (dst) { + /* set noref for now. + * any place which wants to hold dst has to call + * dst_hold_safe() + */ + skb_dst_set_noref(skb, dst); + } +} + +INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb) +{ + return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); +} + +/* + * Throw away all pending data and cancel the corking. Socket is locked. + */ +static void udp_v6_flush_pending_frames(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + + if (up->pending == AF_INET) + udp_flush_pending_frames(sk); + else if (up->pending) { + up->len = 0; + WRITE_ONCE(up->pending, 0); + ip6_flush_pending_frames(sk); + } +} + +static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + if (addr_len < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + /* The following checks are replicated from __ip6_datagram_connect() + * and intended to prevent BPF program called below from accessing + * bytes that are out of the bound specified by user in addr_len. + */ + if (uaddr->sa_family == AF_INET) { + if (ipv6_only_sock(sk)) + return -EAFNOSUPPORT; + return udp_pre_connect(sk, uaddr, addr_len); + } + + if (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + + return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); +} + +/** + * udp6_hwcsum_outgoing - handle outgoing HW checksumming + * @sk: socket we are sending on + * @skb: sk_buff containing the filled-in UDP header + * (checksum field must be zeroed out) + * @saddr: source address + * @daddr: destination address + * @len: length of packet + */ +static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, + const struct in6_addr *saddr, + const struct in6_addr *daddr, int len) +{ + unsigned int offset; + struct udphdr *uh = udp_hdr(skb); + struct sk_buff *frags = skb_shinfo(skb)->frag_list; + __wsum csum = 0; + + if (!frags) { + /* Only one fragment on the socket. */ + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); + } else { + /* + * HW-checksum won't work as there are two or more + * fragments on the socket so that all csums of sk_buffs + * should be together + */ + offset = skb_transport_offset(skb); + skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); + csum = skb->csum; + + skb->ip_summed = CHECKSUM_NONE; + + do { + csum = csum_add(csum, frags->csum); + } while ((frags = frags->next)); + + uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, + csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + } +} + +/* + * Sending + */ + +static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6, + struct inet_cork *cork) +{ + struct sock *sk = skb->sk; + struct udphdr *uh; + int err = 0; + int is_udplite = IS_UDPLITE(sk); + __wsum csum = 0; + int offset = skb_transport_offset(skb); + int len = skb->len - offset; + int datalen = len - sizeof(*uh); + + /* + * Create a UDP header + */ + uh = udp_hdr(skb); + uh->source = fl6->fl6_sport; + uh->dest = fl6->fl6_dport; + uh->len = htons(len); + uh->check = 0; + + if (cork->gso_size) { + const int hlen = skb_network_header_len(skb) + + sizeof(struct udphdr); + + if (hlen + cork->gso_size > cork->fragsize) { + kfree_skb(skb); + return -EINVAL; + } + if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) { + kfree_skb(skb); + return -EINVAL; + } + if (udp_get_no_check6_tx(sk)) { + kfree_skb(skb); + return -EINVAL; + } + if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || + dst_xfrm(skb_dst(skb))) { + kfree_skb(skb); + return -EIO; + } + + if (datalen > cork->gso_size) { + skb_shinfo(skb)->gso_size = cork->gso_size; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, + cork->gso_size); + } + goto csum_partial; + } + + if (is_udplite) + csum = udplite_csum(skb); + else if (udp_get_no_check6_tx(sk)) { /* UDP csum disabled */ + skb->ip_summed = CHECKSUM_NONE; + goto send; + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ +csum_partial: + udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); + goto send; + } else + csum = udp_csum(skb); + + /* add protocol-dependent pseudo-header */ + uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, + len, fl6->flowi6_proto, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + +send: + err = ip6_send_skb(skb); + if (err) { + if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { + UDP6_INC_STATS(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + err = 0; + } + } else { + UDP6_INC_STATS(sock_net(sk), + UDP_MIB_OUTDATAGRAMS, is_udplite); + } + return err; +} + +static int udp_v6_push_pending_frames(struct sock *sk) +{ + struct sk_buff *skb; + struct udp_sock *up = udp_sk(sk); + int err = 0; + + if (up->pending == AF_INET) + return udp_push_pending_frames(sk); + + skb = ip6_finish_skb(sk); + if (!skb) + goto out; + + err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6, + &inet_sk(sk)->cork.base); +out: + up->len = 0; + WRITE_ONCE(up->pending, 0); + return err; +} + +int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct ipv6_txoptions opt_space; + struct udp_sock *up = udp_sk(sk); + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); + struct in6_addr *daddr, *final_p, final; + struct ipv6_txoptions *opt = NULL; + struct ipv6_txoptions *opt_to_free = NULL; + struct ip6_flowlabel *flowlabel = NULL; + struct inet_cork_full cork; + struct flowi6 *fl6 = &cork.fl.u.ip6; + struct dst_entry *dst; + struct ipcm6_cookie ipc6; + int addr_len = msg->msg_namelen; + bool connected = false; + int ulen = len; + int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE; + int err; + int is_udplite = IS_UDPLITE(sk); + int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); + + ipcm6_init(&ipc6); + ipc6.gso_size = READ_ONCE(up->gso_size); + ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags); + ipc6.sockc.mark = READ_ONCE(sk->sk_mark); + + /* destination address check */ + if (sin6) { + if (addr_len < offsetof(struct sockaddr, sa_data)) + return -EINVAL; + + switch (sin6->sin6_family) { + case AF_INET6: + if (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + daddr = &sin6->sin6_addr; + if (ipv6_addr_any(daddr) && + ipv6_addr_v4mapped(&np->saddr)) + ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), + daddr); + break; + case AF_INET: + goto do_udp_sendmsg; + case AF_UNSPEC: + msg->msg_name = sin6 = NULL; + msg->msg_namelen = addr_len = 0; + daddr = NULL; + break; + default: + return -EINVAL; + } + } else if (!READ_ONCE(up->pending)) { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + daddr = &sk->sk_v6_daddr; + } else + daddr = NULL; + + if (daddr) { + if (ipv6_addr_v4mapped(daddr)) { + struct sockaddr_in sin; + sin.sin_family = AF_INET; + sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; + sin.sin_addr.s_addr = daddr->s6_addr32[3]; + msg->msg_name = &sin; + msg->msg_namelen = sizeof(sin); +do_udp_sendmsg: + err = ipv6_only_sock(sk) ? + -ENETUNREACH : udp_sendmsg(sk, msg, len); + msg->msg_name = sin6; + msg->msg_namelen = addr_len; + return err; + } + } + + /* Rough check on arithmetic overflow, + better check is made in ip6_append_data(). + */ + if (len > INT_MAX - sizeof(struct udphdr)) + return -EMSGSIZE; + + getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; + if (READ_ONCE(up->pending)) { + if (READ_ONCE(up->pending) == AF_INET) + return udp_sendmsg(sk, msg, len); + /* + * There are pending frames. + * The socket lock must be held while it's corked. + */ + lock_sock(sk); + if (likely(up->pending)) { + if (unlikely(up->pending != AF_INET6)) { + release_sock(sk); + return -EAFNOSUPPORT; + } + dst = NULL; + goto do_append_data; + } + release_sock(sk); + } + ulen += sizeof(struct udphdr); + + memset(fl6, 0, sizeof(*fl6)); + + if (sin6) { + if (sin6->sin6_port == 0) + return -EINVAL; + + fl6->fl6_dport = sin6->sin6_port; + daddr = &sin6->sin6_addr; + + if (np->sndflow) { + fl6->flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; + if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) { + flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + } + } + + /* + * Otherwise it will be difficult to maintain + * sk->sk_dst_cache. + */ + if (sk->sk_state == TCP_ESTABLISHED && + ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) + daddr = &sk->sk_v6_daddr; + + if (addr_len >= sizeof(struct sockaddr_in6) && + sin6->sin6_scope_id && + __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) + fl6->flowi6_oif = sin6->sin6_scope_id; + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + + fl6->fl6_dport = inet->inet_dport; + daddr = &sk->sk_v6_daddr; + fl6->flowlabel = np->flow_label; + connected = true; + } + + if (!fl6->flowi6_oif) + fl6->flowi6_oif = READ_ONCE(sk->sk_bound_dev_if); + + if (!fl6->flowi6_oif) + fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; + + fl6->flowi6_uid = sk->sk_uid; + + if (msg->msg_controllen) { + opt = &opt_space; + memset(opt, 0, sizeof(struct ipv6_txoptions)); + opt->tot_len = sizeof(*opt); + ipc6.opt = opt; + + err = udp_cmsg_send(sk, msg, &ipc6.gso_size); + if (err > 0) + err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, fl6, + &ipc6); + if (err < 0) { + fl6_sock_release(flowlabel); + return err; + } + if ((fl6->flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { + flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + } + if (!(opt->opt_nflen|opt->opt_flen)) + opt = NULL; + connected = false; + } + if (!opt) { + opt = txopt_get(np); + opt_to_free = opt; + } + if (flowlabel) + opt = fl6_merge_options(&opt_space, flowlabel, opt); + opt = ipv6_fixup_options(&opt_space, opt); + ipc6.opt = opt; + + fl6->flowi6_proto = sk->sk_protocol; + fl6->flowi6_mark = ipc6.sockc.mark; + fl6->daddr = *daddr; + if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr)) + fl6->saddr = np->saddr; + fl6->fl6_sport = inet->inet_sport; + + if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) { + err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, + (struct sockaddr *)sin6, + &fl6->saddr); + if (err) + goto out_no_dst; + if (sin6) { + if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { + /* BPF program rewrote IPv6-only by IPv4-mapped + * IPv6. It's currently unsupported. + */ + err = -ENOTSUPP; + goto out_no_dst; + } + if (sin6->sin6_port == 0) { + /* BPF program set invalid port. Reject it. */ + err = -EINVAL; + goto out_no_dst; + } + fl6->fl6_dport = sin6->sin6_port; + fl6->daddr = sin6->sin6_addr; + } + } + + if (ipv6_addr_any(&fl6->daddr)) + fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ + + final_p = fl6_update_dst(fl6, opt, &final); + if (final_p) + connected = false; + + if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr)) { + fl6->flowi6_oif = np->mcast_oif; + connected = false; + } else if (!fl6->flowi6_oif) + fl6->flowi6_oif = np->ucast_oif; + + security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6)); + + if (ipc6.tclass < 0) + ipc6.tclass = np->tclass; + + fl6->flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6->flowlabel); + + dst = ip6_sk_dst_lookup_flow(sk, fl6, final_p, connected); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + dst = NULL; + goto out; + } + + if (ipc6.hlimit < 0) + ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6, dst); + + if (msg->msg_flags&MSG_CONFIRM) + goto do_confirm; +back_from_confirm: + + /* Lockless fast path for the non-corking case */ + if (!corkreq) { + struct sk_buff *skb; + + skb = ip6_make_skb(sk, getfrag, msg, ulen, + sizeof(struct udphdr), &ipc6, + (struct rt6_info *)dst, + msg->msg_flags, &cork); + err = PTR_ERR(skb); + if (!IS_ERR_OR_NULL(skb)) + err = udp_v6_send_skb(skb, fl6, &cork.base); + /* ip6_make_skb steals dst reference */ + goto out_no_dst; + } + + lock_sock(sk); + if (unlikely(up->pending)) { + /* The socket is already corked while preparing it. */ + /* ... which is an evident application bug. --ANK */ + release_sock(sk); + + net_dbg_ratelimited("udp cork app bug 2\n"); + err = -EINVAL; + goto out; + } + + WRITE_ONCE(up->pending, AF_INET6); + +do_append_data: + if (ipc6.dontfrag < 0) + ipc6.dontfrag = np->dontfrag; + up->len += ulen; + err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), + &ipc6, fl6, (struct rt6_info *)dst, + corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); + if (err) + udp_v6_flush_pending_frames(sk); + else if (!corkreq) + err = udp_v6_push_pending_frames(sk); + else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) + WRITE_ONCE(up->pending, 0); + + if (err > 0) + err = np->recverr ? net_xmit_errno(err) : 0; + release_sock(sk); + +out: + dst_release(dst); +out_no_dst: + fl6_sock_release(flowlabel); + txopt_put(opt_to_free); + if (!err) + return len; + /* + * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting + * ENOBUFS might not be good (it's not tunable per se), but otherwise + * we don't have a good statistic (IpOutDiscards but it can be too many + * things). We could add another new stat but at least for now that + * seems like overkill. + */ + if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { + UDP6_INC_STATS(sock_net(sk), + UDP_MIB_SNDBUFERRORS, is_udplite); + } + return err; + +do_confirm: + if (msg->msg_flags & MSG_PROBE) + dst_confirm_neigh(dst, &fl6->daddr); + if (!(msg->msg_flags&MSG_PROBE) || len) + goto back_from_confirm; + err = 0; + goto out; +} + +static void udpv6_splice_eof(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct udp_sock *up = udp_sk(sk); + + if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk)) + return; + + lock_sock(sk); + if (up->pending && !udp_test_bit(CORK, sk)) + udp_v6_push_pending_frames(sk); + release_sock(sk); +} + +void udpv6_destroy_sock(struct sock *sk) +{ + struct udp_sock *up = udp_sk(sk); + lock_sock(sk); + + /* protects from races with udp_abort() */ + sock_set_flag(sk, SOCK_DEAD); + udp_v6_flush_pending_frames(sk); + release_sock(sk); + + if (static_branch_unlikely(&udpv6_encap_needed_key)) { + if (up->encap_type) { + void (*encap_destroy)(struct sock *sk); + encap_destroy = READ_ONCE(up->encap_destroy); + if (encap_destroy) + encap_destroy(sk); + } + if (udp_test_bit(ENCAP_ENABLED, sk)) { + static_branch_dec(&udpv6_encap_needed_key); + udp_encap_disable(); + } + } +} + +/* + * Socket option code for UDP + */ +int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + if (level == SOL_UDP || level == SOL_UDPLITE) + return udp_lib_setsockopt(sk, level, optname, + optval, optlen, + udp_v6_push_pending_frames); + return ipv6_setsockopt(sk, level, optname, optval, optlen); +} + +int udpv6_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + if (level == SOL_UDP || level == SOL_UDPLITE) + return udp_lib_getsockopt(sk, level, optname, optval, optlen); + return ipv6_getsockopt(sk, level, optname, optval, optlen); +} + +static const struct inet6_protocol udpv6_protocol = { + .handler = udpv6_rcv, + .err_handler = udpv6_err, + .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, +}; + +/* ------------------------------------------------------------------------ */ +#ifdef CONFIG_PROC_FS +int udp6_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) { + seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); + } else { + int bucket = ((struct udp_iter_state *)seq->private)->bucket; + struct inet_sock *inet = inet_sk(v); + __u16 srcp = ntohs(inet->inet_sport); + __u16 destp = ntohs(inet->inet_dport); + __ip6_dgram_sock_seq_show(seq, v, srcp, destp, + udp_rqueue_get(v), bucket); + } + return 0; +} + +const struct seq_operations udp6_seq_ops = { + .start = udp_seq_start, + .next = udp_seq_next, + .stop = udp_seq_stop, + .show = udp6_seq_show, +}; +EXPORT_SYMBOL(udp6_seq_ops); + +static struct udp_seq_afinfo udp6_seq_afinfo = { + .family = AF_INET6, + .udp_table = &udp_table, +}; + +int __net_init udp6_proc_init(struct net *net) +{ + if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops, + sizeof(struct udp_iter_state), &udp6_seq_afinfo)) + return -ENOMEM; + return 0; +} + +void udp6_proc_exit(struct net *net) +{ + remove_proc_entry("udp6", net->proc_net); +} +#endif /* CONFIG_PROC_FS */ + +/* ------------------------------------------------------------------------ */ + +struct proto udpv6_prot = { + .name = "UDPv6", + .owner = THIS_MODULE, + .close = udp_lib_close, + .pre_connect = udpv6_pre_connect, + .connect = ip6_datagram_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .init = udpv6_init_sock, + .destroy = udpv6_destroy_sock, + .setsockopt = udpv6_setsockopt, + .getsockopt = udpv6_getsockopt, + .sendmsg = udpv6_sendmsg, + .recvmsg = udpv6_recvmsg, + .splice_eof = udpv6_splice_eof, + .release_cb = ip6_datagram_release_cb, + .hash = udp_lib_hash, + .unhash = udp_lib_unhash, + .rehash = udp_v6_rehash, + .get_port = udp_v6_get_port, + .put_port = udp_lib_unhash, +#ifdef CONFIG_BPF_SYSCALL + .psock_update_sk_prot = udp_bpf_update_proto, +#endif + + .memory_allocated = &udp_memory_allocated, + .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc, + + .sysctl_mem = sysctl_udp_mem, + .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), + .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), + .obj_size = sizeof(struct udp6_sock), + .h.udp_table = &udp_table, + .diag_destroy = udp_abort, +}; + +static struct inet_protosw udpv6_protosw = { + .type = SOCK_DGRAM, + .protocol = IPPROTO_UDP, + .prot = &udpv6_prot, + .ops = &inet6_dgram_ops, + .flags = INET_PROTOSW_PERMANENT, +}; + +int __init udpv6_init(void) +{ + int ret; + + ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); + if (ret) + goto out; + + ret = inet6_register_protosw(&udpv6_protosw); + if (ret) + goto out_udpv6_protocol; +out: + return ret; + +out_udpv6_protocol: + inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); + goto out; +} + +void udpv6_exit(void) +{ + inet6_unregister_protosw(&udpv6_protosw); + inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); +} |